1 
2 /*
3  * Copyright 2013 Google Inc.
4  *
5  * Use of this source code is governed by a BSD-style license that can be
6  * found in the LICENSE file.
7  */
8 #include "gm.h"
9 #include "SkBitmap.h"
10 #include "SkRandom.h"
11 #include "SkShader.h"
12 #include "SkXfermode.h"
13 
14 namespace skiagm {
15 
16 /**
17  * Renders overlapping shapes with colorburn against a checkerboard.
18  */
19 class DstReadShuffle : public GM {
20 public:
DstReadShuffle()21     DstReadShuffle() {
22        this->setBGColor(SkColorSetARGB(0xff, 0xff, 0, 0xff));
23     }
24 
25 protected:
26     enum ShapeType {
27         kCircle_ShapeType,
28         kRoundRect_ShapeType,
29         kRect_ShapeType,
30         kConvexPath_ShapeType,
31         kConcavePath_ShapeType,
32         kText_ShapeType,
33         kNumShapeTypes
34     };
35 
onShortName()36     SkString onShortName() override {
37         return SkString("dstreadshuffle");
38     }
39 
onISize()40     SkISize onISize() override {
41         return SkISize::Make(kWidth, kHeight);
42     }
43 
drawShape(SkCanvas * canvas,SkPaint * paint,ShapeType type)44     void drawShape(SkCanvas* canvas,
45                    SkPaint* paint,
46                    ShapeType type) {
47         static const SkRect kRect = SkRect::MakeXYWH(SkIntToScalar(-50), SkIntToScalar(-50),
48                                                      SkIntToScalar(75), SkIntToScalar(105));
49         switch (type) {
50             case kCircle_ShapeType:
51                 canvas->drawCircle(0, 0, 50, *paint);
52                 break;
53             case kRoundRect_ShapeType:
54                 canvas->drawRoundRect(kRect, SkIntToScalar(10), SkIntToScalar(20), *paint);
55                 break;
56             case kRect_ShapeType:
57                 canvas->drawRect(kRect, *paint);
58                 break;
59             case kConvexPath_ShapeType:
60                 if (fConvexPath.isEmpty()) {
61                     SkPoint points[4];
62                     kRect.toQuad(points);
63                     fConvexPath.moveTo(points[0]);
64                     fConvexPath.quadTo(points[1], points[2]);
65                     fConvexPath.quadTo(points[3], points[0]);
66                     SkASSERT(fConvexPath.isConvex());
67                 }
68                 canvas->drawPath(fConvexPath, *paint);
69                 break;
70             case kConcavePath_ShapeType:
71                 if (fConcavePath.isEmpty()) {
72                     SkPoint points[5] = {{0, SkIntToScalar(-50)} };
73                     SkMatrix rot;
74                     rot.setRotate(SkIntToScalar(360) / 5);
75                     for (int i = 1; i < 5; ++i) {
76                         rot.mapPoints(points + i, points + i - 1, 1);
77                     }
78                     fConcavePath.moveTo(points[0]);
79                     for (int i = 0; i < 5; ++i) {
80                         fConcavePath.lineTo(points[(2 * i) % 5]);
81                     }
82                     fConcavePath.setFillType(SkPath::kEvenOdd_FillType);
83                     SkASSERT(!fConcavePath.isConvex());
84                 }
85                 canvas->drawPath(fConcavePath, *paint);
86                 break;
87             case kText_ShapeType: {
88                 const char* text = "Hello!";
89                 paint->setTextSize(30);
90                 canvas->drawText(text, strlen(text), 0, 0, *paint);
91             }
92             default:
93                 break;
94         }
95     }
96 
GetColor(SkRandom * random,int i,int nextColor)97     static SkColor GetColor(SkRandom* random, int i, int nextColor) {
98         static SkColor colors[] = { SK_ColorRED,
99                                     0xFFFF7F00, // Orange
100                                     SK_ColorYELLOW,
101                                     SK_ColorGREEN,
102                                     SK_ColorBLUE,
103                                     0xFF4B0082, // indigo
104                                     0xFF7F00FF }; // violet
105         SkColor color;
106         int index = nextColor % SK_ARRAY_COUNT(colors);
107         switch (i) {
108             case 0:
109                 color = SK_ColorTRANSPARENT;
110                 break;
111             case 1:
112                 color = SkColorSetARGB(0xff,
113                                        SkColorGetR(colors[index]),
114                                        SkColorGetG(colors[index]),
115                                        SkColorGetB(colors[index]));
116                 break;
117             default:
118                 uint8_t alpha = 0x80;
119                 color = SkColorSetARGB(alpha,
120                                        SkColorGetR(colors[index]),
121                                        SkColorGetG(colors[index]),
122                                        SkColorGetB(colors[index]));
123                 break;
124         }
125         return color;
126     }
127 
SetStyle(SkPaint * p,int style,int width)128     static void SetStyle(SkPaint* p, int style, int width) {
129         switch (style) {
130             case 0:
131                 p->setStyle(SkPaint::kStroke_Style);
132                 p->setStrokeWidth((SkScalar)width);
133                 break;
134             case 1:
135                 p->setStyle(SkPaint::kStrokeAndFill_Style);
136                 p->setStrokeWidth((SkScalar)width);
137                 break;
138             default:
139                 p->setStyle(SkPaint::kFill_Style);
140                 break;
141         }
142     }
143 
onDraw(SkCanvas * canvas)144     void onDraw(SkCanvas* canvas) override {
145         SkRandom random;
146         SkScalar y = 100;
147         for (int i = 0; i < kNumShapeTypes; i++) {
148             ShapeType shapeType = static_cast<ShapeType>(i);
149             SkScalar x = 25;
150             for (int style = 0; style < 3; style++) {
151                 for (int width = 0; width <= 1; width++) {
152                     for (int alpha = 0; alpha <= 2; alpha++) {
153                         for (int r = 0; r <= 5; r++) {
154                             SkColor color = GetColor(&random, alpha, style + width + alpha + r);
155 
156                             SkPaint p;
157                             p.setAntiAlias(true);
158                             p.setColor(color);
159                             // In order to get some batching on the GPU backend we do 2 src over for
160                             // each xfer mode which requires a dst read
161                             p.setXfermodeMode(r % 3 == 0 ? SkXfermode::kLighten_Mode :
162                                                            SkXfermode::kSrcOver_Mode);
163                             SetStyle(&p, style, width);
164                             canvas->save();
165                             canvas->translate(x, y);
166                             canvas->rotate((SkScalar)(r < 3 ? 10 : 0));
167                             this->drawShape(canvas, &p, shapeType);
168                             canvas->restore();
169                             x += 8;
170                         }
171                     }
172                 }
173             }
174             y += 50;
175         }
176     }
177 
178 private:
179     enum {
180         kNumShapes = 100,
181     };
182     SkAutoTUnref<SkShader> fBG;
183     SkPath                 fConcavePath;
184     SkPath                 fConvexPath;
185     static const int kWidth = 900;
186     static const int kHeight = 400;
187     typedef GM INHERITED;
188 };
189 
190 //////////////////////////////////////////////////////////////////////////////
191 
MyFactory(void *)192 static GM* MyFactory(void*) { return new DstReadShuffle; }
193 static GMRegistry reg(MyFactory);
194 
195 }
196